A Michigan doctor faces life in prison after he admitted to intentionally misdiagnosing patients with cancer and recommending unnecessary chemotherapy to dying patients.

Dr. Farid Fata pleaded guilty Tuesday to 13 counts of health care fraud, two counts of money laundering and one count of conspiracy to pay and receive kickbacks, reported the Detroit Free Press.

The crimes were part of a moneymaking scheme, he said.

“It is my choice,” Fata told the court. “I knew that it was medically unnecessary.”

Prosecutors plan to seek life in prison for the 49-year-old married father of three, saying the case was “the most egregious” health care fraud their office had ever seen.

“In this case, we had Dr. Fata administering chemotherapy to people who didn’t need it, essentially putting poison into their bodies and telling them that they had cancer when they didn’t have cancer,” said U.S. Attorney Barbara McQuade. “The idea that a doctor would lie to a patient just to make money is shocking.”

Fata made about $35 million as part of a Medicare fraud scheme through his practices in suburban Detroit.

The Lebanon native had about 1,200 patients and received about $62 million from Medicare, although he billed for more than $150 million.

A chemotherapy nurse first reported the wrongdoing in 2010 after a job interview with his practice, where she noticed patients receiving chemotherapy in an incorrect manner.

“I left after an hour and half. I thought this is insane,” said Angela Swantek.

However, she said the state notified her the following year that investigators had found no wrongdoing.

Fata was charged in 2013 by the federal government.

His victims’ families said they were disappointed the surprise guilty plea would prevent a trial, where they might have heard some of the answers they sought.

“I’m curious to understand why they can’t charge him with murder if he is admitting that he knowingly administered these drugs that are toxic when you need them — let alone when you don’t need them,” said Liz Lupo, whose mother died in 2007 after she was treated by Fata. “Why you can’t get him on murder?”

McQuade said investigators did not find enough evidence to charge Fata with murder.